Nigel

I have this problem with my current transmission and the one I had in the car before. The bottom of my car is soaked in tranny fluid. The metal lining is very soft. It is possible to remove the sleeve, but I've never been able to find a new replacement. Perhaps there's a more compliant seal that could be used? Nigel

I said in my post that you quoted that I was assuming equal pad coefficients of friction, and I clarified later that my calculation was based on the smaller SX rear caliper. Regardless, yes you can adjust bias with different pad compounds, and you may be able to get the V6 Toyota/later SX caliper combo to work ok with the right pad combination. The challenge is finding a published friction rating for a given pad so that you're not just swapping pads at random until you find a combination that works. Many pads have a 2 letter code printed on them that provides the friction range, but you can't get that until after you bought the pads. For my own personal setup, which includes AZC Wilwood fronts and my own Jag/Lincoln rear design (http://forums.hybridz.org/topic/113199-yet-another-rear-drum-to-disk-conversion-option/), I started out with some EE code pads (0.25 to 0.35) in the back that I had left over. As I suspected, based on the math, even with full rear line pressure, I couldn't get the rears to lock. I then switched to EBC Yellow Stuff GG code pads (0.45 to 0.55), which the math indicated would be a better match, and sure enough, I've had to decrease rear pressure by three turns on my adjustable prop valve to achieve a slight front bias. I guess countless physicists and hundreds of years of experimental data must all be wrong then? The force of friction is due to the coefficient of friction between two objects and the force pushing them together. That's all. Surface area is effectively irrelevant. If you place a 50 pound block on one square inch, you have 50 lbs per square inch of force. But doubling the surface area to 2 square inches does not double the weight applied. You're still applying the same 50 lbs block, but now to two square inches, so in effect you're now only applying 25 lbs per each square inch. You've doubled the area, but halved the force. That's why surface area is irrelevant. Nigel

It makes me feel a little better to know that not all OEM discs have grooves. Looking at some pictures I took of my clutch pieces when everything was apart, I noticed that the discs with the external fingers that go between the new discs have slots radiating out across the face. That should allow oil to get between the discs. However, from my pictures, I can't tell if the slots are on both sides of those discs. I've already tried changing brands of oil. I started with Lucas oil, which came with modifier in it. It was binding badly, so I added about 1/2 a bottle of modifier (spilled half of it on the floor!), and did a bunch of figure 8's. That helped, but not enough. I added a additional full tube of modifier and it improved more, but still not enough. I then drained it all and switched to Redline, with two full bottles of modifier. At first, I thought that did the trick, but the binding came back again. It doesn't do it all the time, but it's enough to be really irritating. Strangely, I can do figure 8's under power with no problem. But more often than not, it will happen maneuvering around a parking lot. It could be my imagination, but it seems to be worse after reversing out of a parking space. Just once I'd like to put something in my Z and have it work right the first time! Nigel

From what I recall, the material used for the new discs was matched to that of the OEM discs. Perhaps it has something to do with the surface finish? The OEM discs have rings machined into the surface, whereas the discs from the group buy do not. Nigel

How much modifier did you end up using? I seem to recall you had another post about this but I can't find it now. I finally got around to putting my extra group buy clutch discs in, and now I'm wishing I hadn't bothered. I didn't add any shims, so the breakaway is about 45 to 50lbs and I've got two bottles of modifier in it but it's still popping and binding way too much to my liking, even after 1500 miles of driving. It feels like someone is pounding on the diff with a hammer when turning at slow speed and it makes me cringe every time it happens. Driving in the rain is even worse. I could feel and hear it binding even at 35 to 40 mph on sweeping turns. Maneuvering in a wet parking lot is a miserable experience. I'm going to try one more bottle of modifier. But it seems rather ridiculous to have to run 20% of the diff fluid as friction modifier. Or is this typical. But if that doesn't minimize it to an acceptable level, as much as I hate the thought of tearing everything apart again, those extra discs are coming out. I know there are lots of other people using the group buy discs though, but I haven't seen much feedback from those people. If you're using them and haven't had any issues, what's yor secret? Nigel

A reading of 13.4 volts immediately after charging is not unusual. Since you don't have the S terminal connected, what voltage going into the alternator are you talking about? As I already indicated, the S terminal is what tells the alternator how much voltage to put out. Without connecting that, the alternator has no way of regulating it's output to keep up with demands on the electrical system and keep the battery charged. That's what it's there for. 13.5V out from the alternator is already on the low side for charging, and with the voltage drop to the battery (1V isn't excessive), you're undercharging the battery. Nigel

Connect the S terminal to the positive battery post so the alternator knows what voltage to put out to keep the battery charged. As for the volt you're loosing, after 40 years some of the wire connections in the charging circuit have likely loosened up and/or are corroded.

Where do you have the voltage sensing wire for the alternator connected? Nigel

Does the blaster 2 require the ballast resistor?

No problem. Maybe it was the Haynes manual I read it in. They tend to provide more basic info. Regardless, the rule of thumb is to start farthest from the master cylinder. Strangely enough, that turns out to be the driver's side rear if you look at the actual line lengths. Nigel

3ryce, what exactly are you trying to do? You haven't provided any information on your ignition system. Why do you think you need a tach adapter? The fact that you're asking if you need an MSD 6AL to use a tach adapter tells me you need to stop and do a lot of reading before you go any further. You need a tach adapter if you have an MSD 6AL. You don't add an MSD 6AL because you have a tach adapter. Or, are you asking if the tach adapter only works with the 6AL? I can't tell. Also, no, you can't use the temperature sensor wire as a 12V source. Nigel

Driver's side rear then passenger side rear. Passenger side front then driver's side front. Is this not in the service manual? Nigel

Any SX 5 speed will work, but they are not all created equal. Later years have thicker gears and a larger diameter mainshaft (documented in my 240SX install guide). Also, IIRC the SX box has a shorter fifth gear (higher revs) than the ZX 5 speeds. If you want to lower your cruising rpm, you have to look at the diff ratio and tire size as well. Nigel

I never said it didn't. I never said other thermostats weren't necessary. But we're talking about 30+ year old cars with poor quality oils, inconsistent block and head castings, less efficient radiators, and questionable aerodynamics. So, Nissan offered a few different thermostats to hedge their bets. I have the competition hood vent and I cut the biggest hole in the hood that I could. It's the length of the block and the width of the hood bulge. I didn't see much of an improvement in hot starts. With out some sort of fan to force the hot air out, it still gets trapped in the engine bay when the car is stationary. I don't believe a hot fuel rail is the real issue. My fuel rail is isolated by rubber, and it only feels warm when I have hot start issues. I believe the issue is with the heat of the injectors themselves. They're right next to the head, and only inches away from the exhaust manifold. I've touched them, and they get scorching hot. This is the inherent problem with a non-cross flow head. I've found that even repeated priming of the rail isn't enough to flush out the hot fuel from the injectors. It only clears out the rail. I've wondered if getting rid of the injector retainers would help, if they're acting like an insulator to keep the heat in. Nigel

I've been battling hot start issues from pretty much day one after my L28 Turbo conversion in my 240Z. I can get it to fire up, but it dies almost immediately. I'm running SDS EFI fuel injection, with a '75 intake manifold, RX-7 Injectors with a custom barbed fuel rail that's isolated from the manifold. I'm running the 82C thermostat. I have zero issues with over heating. The coolant runs in the 180's on the highway. The car ran at the track in Nashville in mid 90F temps, and I've sat idling for over an hour in 90F heat at a border crossing. The coolant will get up into the 190's in those conditions but that because that's where I have my electric fan set to operate (SPAL PWM variable speed controller). The SDS system includes a fuel prime, but it doesn't help. Even repeatedly cycling it makes no real significant difference. Fuel pressure holds after the prime. Over the years, I've tried a number of things (just about everything mentioned in this thread) to address the hot start issue, but none have solved it. They include: Moving the air temp sensor from the intake manifold to the outlet end tank of the intercooler. Multi-layer reflective heat shield under the intake manifold. Insulating blanket over the exhaust manifold. SS Turbine heat shield. Exhaust wrap on the down pipe. Reflective sheilding wrap on fuel lines in the transmission tunnel Reflective sheilding wrap on the fuel rail Fuel cooler after the fuel pump Competition hood vent I've researched hot start issues on this forum and others for years and years, but I've never been able to find a conclusive common denominator for why some people have hot start issues and others don't. This is the first time I've heard of using a cooler thermostat in the context of combating hot start issues. There's no evidence that I can find that Nissan intended the tropical thermostat to be used to combat hot start issues. I can't even find any definition in the factory service manual as to what conditions each of thermostats available should be used under. If solving hot start issues was as simple as using a colder thermostat, then why did they waste time and money developing and installing injector cooling fans? If it's due to emissions requirements, then how could they offer a tropical thermostat in the first place? Based on the era these cars were made, I think the purpose of a tropical thermostat had to do with the limitations of the oil and coolant of the day more than anything else. Regardless, using that approach to keep the injectors cooler may very well work. But this seems like just as much a band aid solution as anything else, since it's not without negative consequence. I'm not a fan of reducing efficiency by sending more energy into the cooling system rather than making the car move forward. I'm also reluctant to start messing with a system in my car that in functions perfectly well in every other way. The only thing that I've found that helps my hot start issue is by manually running the radiator fan after shut-down for a few minutes. So, I have a couple of ideas in mind that I may try. I may lower the set point the electric fan kicks in. But I don't want to go so low that it's running while cruising around. It starts out at 50% at around 190F. And this would only help if I let the car idle for a while before turning it off. I do have an injector cooling fan that I may install. I found a handy inexpensive timer module (Velleman VM188) that I was going to use in combination with a temperature switch to control it. But a simpler solution may be to use the timer to keep the SPAL fan controller powered for X minutes after the ignition is shut off so it can continue to run the fan as needed. I think this is what I'm going to try first. Since the SPAL controller only runs the fan as hard as is needed, it shouldn't put too much of a strain on the battery. I'll be hooking this up this weekend. Nigel

I went from 225's on +4 rims to 255's on -13 rims and I didn't notice a huge difference in effort. In both cases, I found any kind of slow speed driving to be very difficult. But I'm 6'7" tall, and with the steering wheel I had, my arms were straight out. This gave me no leverage. I then switched to a wheel and adapter combination (Momo adapter + NRG short quick release + deep dish NRG wheel) that moved the steering wheel several inches closer. It was like I suddenly added power steering to my Z! I couldn't get over the difference. I'm now able to maneuver in parking lots without straining to turn the wheel, and I have a lot more confidence handling the car at speed. I realize not every one is as tall as me, but it's still worth considering your position to the steering wheel. Your elbows should be at about a 90 degree angle. Nigel

I pretty much did what HB280ZT shows on page one of this thread. Nigel

My mount is fine, but I think the bolt that is included with it too long. On mine it was boring right into the polly, and felt like it was hitting something. I shortened it by at least 1/4"

Fair enough. The WC upgrade sounds interesting. I'll be watching to see how that turns out... Nigel

I'm curious what specifically you have against the Nissan 5 speed? Nigel

Update: I did take the diff to the driveline shop. They checked it over and made a small adjustment to the side shims. The backlash is now down to 0.004", which is slightly tighter than minimum spec. This made me a bit nervous, but I finally got to drive the car yesterday and so far, it appears the shop knew what they were doing. The diff 'feels' great. There's even less vibration than the old 3.7. No unusual noises either, at least not up to 75mph. The clunking that I was experiencing before when getting on and off the throttle is now gone too. I was going to say it was definitely the backlash in the old diff that was causing that. However, it just occurred to me that there's a possibility that the bolt attaching the diff bushing to the Ron Tyler bracket may have been slightly loose. Unfortunately, I wasn't able to check the preload again. All the torque wrenches we have at work were sent out for calibration. I'm going on a long drive this coming weekend. Fingers crossed that this differential is in the car for life. Nigel

I just fell into this trap, and I'm now burning in hell as a consequence. Two events missed and two weeks lost so far trying to get it sorted out. I read through the Typical Install page a number of times, but by the time I actually got to the install, this particular issue didn't stick in my memory for some reason. Probably because one single sentence stating that the end of the control arm "MAY" need to be trimmed down and a tiny picture of what appears to be an unmodified control arm is hardly adequate to draw attention to what is a HUGE interference issue that will seriously damage the rotors if you so much as try to move the car, never mind drive it! All I did was back the car up ten feet out of the garage. It started out ok, but as the suspension settled the car was getting harder to move and I started to hear a grinding sound. I initially thought it was the parking brake hanging up on my rear disk conversion that I had just designed and installed. But after investigating that thoroughly, I finally realized that it must be the front brakes. Sure enough, with the car on the ground, I now noticed that the front control arms were jammed into the rotors, and there was a groove worn into the rotors. I then found this thread and others like it and discovered the lengths to which people have had to go to ensure adequate rotor clearance. We're not talking about skimming a bit of material off the control arm as a precaution, but rather lopping off everything beyond the ball joint in some cases. If I'd seen pictures of how much work people have actually had to do, I would have remembered that. I was meticulous about every other part of the installation. I've since had to cut away almost all of the ends of the control arms to be absolutely sure nothing will interfere. I've also had the inner face of both rotors turned to remove the grooves by a friend in the machine shop at work. Both needed about 0.010" cut from the inner face. Unfortunately, to add insult to injury, the rotors apparently didn't go on the lathe right, because the inner face of one rotor ended up with 0.005" runout, and the other had 0.003". So, today I had them cut again on an actual brake lathe. Hopefully that finally does it. But I don't know if I've exceeded the limit of how much can be removed. Wilwood says zero, but that seems extreme, and I'm not buying another set of brand new rotors. I accept responsibility for overlooking a particular step in the process shown on the Install page. But a much, much better job could be done to bring this to peoples attention in the first place. Some large, clear pictures showing the extremes to which you may have to go to get adequate clearance, and some highlighted text are a must. Heck, I'd say including a warning sheet in the box of parts wouldn't be excessive. The consequences of missing this step are severe and it's well outside of the scope of a typical brake job. This whole experience has been infuriating. Nigel

I was just there today! I've know Greg (the owner) and Mike (the manager) for 20 years now, and I've been going to the shop all that time. They have a good repulation locally. As thedarkie mentioned, the place is always packed with Z's.

Here's a picture with hood closed...